Yellow Day chronicles a young man's life-changing and inspirational journey through the mysterious Yellow Day. To many, the Yellow Day is simply a fun day celebrating outreach at a kid's camp, but to some, God bestows visions and miracles, transforming their lives. For this young man, the Yellow Day becomes an imaginative adventure: showing him true heroes, challenging him to face his fears, find love, and inviting him to accept grace, so that he can be shaped into who he is meant to be.

Larry Donner, an author with a cruel ex-wife, teaches a writing workshop in which one of his students, Owen, is fed up with his domineering mother. When Owen watches a Hitchcock classic that seems to mirror his own life, he decides to put the movie's plot into action and offers to kill Larry's ex-wife, if Larry promises to murder his mom. Before Larry gets a chance to react to the plan, it seems that Owen has already set things in motion.